Grinding and truing machine



Oct. 30, 1956 Filed June 9, 1.954

A. J. LAVAUD GRINDING AND TRUING MACHINE] 6 Sheets-Sheet 1 a WJJQLQ gamu Oct. 30, 1956 A. J. LAVAUD GRINDING AND TRUING MACHINE 6 Sheet5-$hee t 2 Filed June 9, 1954 Oct. 30, .1956 A. J. LAVAUD 2,765,477

GRINDING AND TRUING MACHINE Filed June 9, 1954 6 Sheets-Sheet 3 I 76 FIG'5 4 I) wl lllllllllllfll v FIG] Oct. 30, 1956 A. J. LAVAUD 2,768,477

GRINDING AND TRUING MACHINE Filed June 9, 1954 6 Sheets-Sheet 4 F/GB Oct. 30, 1956 A. J. LAVAUD 2,763,477

- GRINDINGANDTRUINGMACHINE F/GJO Oct. 30, 1956 A. J. LAVAUD 2,768,477

GRINDING AND TRUING MACHINE Filed June 9, 1954 6 Sheets-Sheet 6 FIG. 11

United States PatentO GRINDING AND TRUING MACHINE Armand Jean Lavaud, Paris, France, assignor to Martin & Cie, Paris, France, a company of France Application June 9, 1954, Serial No. 435,535 Claims priority,applieation France August 17, 1953 1 Claim. (CI. 5195) My invention has for its object a grinding and truing machine incorporating a number of novel features, whereby. it-distinguishes as highly improved over all prior machines of the same type.

According to a primary feature of my invention, the support for the spindle carrying the grinding wheel and the motor driving said spindle are both mounted on a slider adapted to move vertically inside an upright adapted to pivot round a vertical axis over the conventional transverse'carriage of the machine, while the spindle for the grinding wheel is pivotally mounted so as to revolve round a horizontalaxis, the combination of the three movements thus provided allowing the grinding wheel to assume any desired location in space "According to a further feature of my invention, the means controlling the vertical movements of the slider carrying the spindle support and the motor include an arrangement for balancing the Weight of the system including the motor and the spindle support and for compensating clearances, said arrangement being advantageously constituted by a hydraulic piston rigid with a worm controlling the movements of the slider and submitte'dat its lower end to an adjustable pressure of compressed fluid.

According to a further feature of my invention, the horizontal movements of the transverse carriage, carrying the above-mentioned vertical upright, over the frame of the machine are obtained through a hydro-mechanical control system providing for permanent compensation of play and constituted advantageously by the combination of a-worm rotating under the action of a control member soas to produce the longitudinal movements of an elong'ated'nut, with a hydraulic piston rigid with the transverse carriage, said piston being caused 'to abut against said elongated nut so as to be driven by the latter to provide for the positive forward shifting of the transverse carriage while in contradistinction said piston is actuated directly by compressed fluid during the rapid return movement of said transverse carriage.

According to a still further feature of my invention, the longitudinal carriage of the machine which is, as usual, slidingly mounted on the frame of the machine includes lateral guiding rollers the clearance of which with reference to the frame is; preferably adjustable, so as to cut out any possible rocking of said longitudinal carriage when it] is mounted in overhanging conditions.

According to yet another feature of my invention, we obtain'auniform angle of cut at any stage whatever in the sharpening of tools with multiple series of teeth, such as milling cutters, by producing an angular shifting of the headstock spindle carrying the tool to be sharpened instead of the relative movement of the carriage serving asa support for the headstock with reference to the grinding'wheel, which movement normally resorted to hitherto led to cutting angles the values of which varied with the depth; of cut.

This last feature may be associated with means for sharpening or grinding tools provided with helical cutting edges, said means including a member adapted to assume an adjustable angular setting with reference to the frame of the machine and producing during the reciprocatory movements of the longitudinal carriage on the latter, transverse movements of a rod producing in its turn an angular shifting of a pulley, which shifting is transmitted to the spindle of the headstock, the angular shifting of the spindle being proportional to the longitudinal movement of the carriage.

I have illustrated in the accompanying drawings by way of example and by no means in a limiting sense, a preferred embodiment of the object of my invention. In said drawings:

Fig. 1 is a front elevational view of the machine.

Fig. 2 is a side elevational view thereof.

Fig. 3 is a view of the machine from above.

Fig. 4 is a horizontal sectional view of the vertical pivoting upright.

Fig. 5 is a partial vertical cross-section of said vertical pivoting upright.

Fig. 6 is a longitudinal sectional view of the transverse carriage.

Fig. 7 is a sectional view across the lead screw and the transverse carriage shown in Fig. 6.

Fig. 8 is a transverse sectional view of the longitudinal carriage, the transverse carriage being shown partly elevationally and partly sectionally.

Fig. 9 is a sectional elevational view passing through the axis of the headstock spindle of the machine, when serving for the sharpening of a tool.

Figs. 10 and 11 are respectively a partly sectional elevational view and a plan view of themeans controlling the headstock spindle of the machine when sharpening a tool providing a helical cut.

In Figs. 1 to 3, A designates the frame of the machine forming a box structure and carrying directly as in the case of ordinary cylindrical grinding machines, the lon gitudinal carriage B and the transverse carriage C, which both slide directly over the frame of the machine. D -D designate the 'ha'ndwheels controlling the movementsof the longitudinal carriage B conventionally through a pinion and a rack which are not illustrated. The longitudinal carriage may as well be controlled hydraulically.

Over the longitudinal carriage B is laid an auxiliary carriage E adapted to be angul-arly shifted in a horizontal plane and to receive as auxiliaries the supports for the parts required for holding various pieces of work as desired.

F designates a handwheel controlling the hydromechanical transmission controlling in its turn through a Worm and nut arrangement, the movements of the transverse carriage C, as disclosed with further detail hereinafter. i

On the transverse'carriage C is mounted an upright 1 adapted to pivot over a support 2 round a vertical axis X-X'. Inside said pivoting upright 1, a slider is adapted to be shifted vertically along slideways described hereinafter. Said slid-er carries the wheel-driving motor and the support for the spindle G driving the grinding Wheel. Said spindle may also rock round a horizontal axis YY- as shown in Fig. 5.

Thus, the association of the revoluble mounting of the upright 1 adapted to pivot about a vertical axis, of the vertical slidingmovement of the spindle support and of the mounting of the spindle G for pivoting about a horizontal axis, is very easy to give the latter any desired position in space. This forms a chief feature of the invention and distinguishes it from all prior grinding and truing machines.

Figs. 4 and 5 show on a larger scale the pivoting upright 1 and its slideways 3 along which the slider 4 is adapted to slide vertically together with the motor H cont-rolling:

the spindle G and with the carrier I for the latter. A vertical worm (Fig. 5) the upper end of which is rigid with the vertically movable slider 4 provides for the rising and sinking movements of thesupport for the carrier I of the spindle and of the motor H. Said worm 5 isdriven vertically by a bevel pinion 6 threaded interiorly and forming a nut engaging said worm. Said bevel pinion 6 is revolubly carried inside a ball-bearing 7 mounted inside a sleeve 8 rigid with the upright 1. Said bevel pinion 6 is controlled by a further bevel pinion 9 rigid with a spindle 10 revolving inside ball bearings 11 carried in a horizontal sleeve 12 also rigid with the upright 1. The spindle 10 is controlled by the handwheel 13 so as to provide for the rapid vertical movement of the slider 4 in the slideway 3.

When it is desired to make the slider 4 progress by a predetermined amount, the control knob 14 is used for actuation of the spindle 10 through the agency of the gears 15, 16 and 17. At its lower end, the worm 5 carries a piston 18 moving inside a cylinder 19 forming a downwardly directed extension for the sleeve 8. A pipe 20 is adapted to send oil under pressure into the cylinder 19, underneath the piston 18, so that the upwardly directed stress exerted on the lower surface of said piston may be larger than the sum of the vertical stresses exerted downwardly through the slider 4 and the worm 5 and due to the weight of the system including the motor H and the spindle G. This arrangement allows constantly balancing the weight of said system and permanently compensating for the clearances produced by the reaction of the grinding wheel in contact with the work. This also cuts out the rising or release of the grinding wheel at the moment of its engagement with the work, either when it is operating sideways on the revolving surface thereof or tangentially with reference thereto.

Fig. 6 is a detail view on a larger scale of the hydromechanical control means for the transverse carriage C.

These control means include a piston 21 rigidly secured at 22 to the transverse carriage C and moving inside a cylinder 23 rigid with the frame A of the machine.

24 is a control worm controlled by the rotation of the handwheel F. Said control worm drives, when it rotates, an elongated nut 25 provided with a T-shaped rib at 26 (Fig. 7) engaging a corresponding recess 27 formed inside the carriage C; this prevents 'any rotation of the elongated nut 25 which can thus only move longitudinally with reference to the carriage C.

The inner end of the nut 25 includes a piston-forming section 28 moving inside the above-mentioned cylinder 23. A pipe 29 feeds oil under pressure into the annular space between the first-mentioned piston 21 and the cylinder 23 and urges said piston 21 into abutting relationship with the nut 25.

Any positively controlled longitudinal movement of the nut 25 obtained through actuation of the handwheel F will consequently produce a corresponding movement of the piston 21 and thereby of the transverse carriage C.

As the tapping of the nut 25 engaging the worm 24 will always produce a stress in the direction of the arrow f, the clearances are always compensated for in the same direction. In order to relieve the stresses in the control means, it is possible to cut out the oil pressure applied through the port 29 whenever the transverse carriage C moves rearwardly.

The above-mentioned hydro-mechanical control allows thereby executing a rapid return movement of the transverse carriage C. To this end and as just mentioned, oil under pressure is fed no longer into the port 29 but through the channel 30 opening inside the piston 21 so that the oil may exert a pressure on the outer larger surface of the piston which is thus urged hydraulically towards the rear and carries along with it the transverse carriage C to which it is secured at 22. The transverse carriage C then slides rearwardly while the T-sh'aped rib 4 26 of the nut 25 which is then stationary, forms a guide for the recess 27 of the carriage.

The handwheel F is then actuated so as to return the nut 25 into engagement with the piston 21; any springoperated or the like damping means, such as 31 for instance, may be provided for damping the shocks produced by the nut when engaging the piston 21.

The worm 24 may also be controlled by hand through the handwheel 32 (Fig. 3) located on one side of the machine, an angular transmission 33, a shaft 34 and a couple of sprocket wheels 3536 (Fig. 8).

It should be remarked that the longitudinal carriage B is provided preferably with four lateral rollers 37 (two on each side of the carriage) mounted each on a spindle adapted to be shifted eccentrically for adjustment of the clearances between the carriage and the frame or else for exerting an initial pressure between said parts with a view to providing a greater rigidity for the whole system and improving the grade of the grinding procedure.

J designates the races for the roller bearings through which the longitudinal carriage B is carried when moving over the frame A.

The rollers 37 allow cutting out any rocking movement of the longitudinal carriage B in the case of an overhanging mounting as required for instance when sharpenin g a large-sized milling cutter.

A further feature of my invention resides in the particular design of the headstock driving the piece of work in the case of a sharpening of helical tools or of a helical grinding with a view to obtaining a uniform angle of cut.

Figs. 9 to 11 show at 38 the body of the headstock K carried by the longitudinal carriage B, while 39 designates the spindle of said headstock on which is mounted the work to be sharpened or ground.

On the frame A of the machine is mounted a support 40 provided with a stationary horizontal plate 41 on which rests a plate 43 which may be angularly adjusted round the axis of the bolt 42 assembling said two plates 41 and 43 (Fig. 10).

A screw 44 serves for giving the desired angular setting of the plate 43 in its horizontal plane by shifting a socket 44' (Fig. 11) rigid with the upper angularly shiftable plate 43, with reference to the screw support 44 rigid with the lower stationary plate 41.

The plate 43 carries a straight edge member 45 along the upper edges of which a carriage 47 slides through the agency of rollers 46; said carriage 47 is provided with a vertical pivot 48 for a horizontal rod 49 sliding inside a slideway 50 carried by the body 38 of the headstock K. 51 designates the pulley driving the spindle 39 of the chuck. A first steel strip 52 is secured at 53 to the rod 49 and at 54 to the pulley 51.

A second steel strip 55, wound in the opposite direction over the pulley 51, is secured at 56 to the latter and at 57 to the rod 49. This arrangement provides for the uniform tensioning of the steel strips 52 and 55 whereby the spindle 39 is rocked in both directions when the longitudinal carriage reciprocates in the direction of the arrows f of Fig. 11.

As a matter of fact, if the member 58 rigid with the pulley 51 is released with reference to the body 38 of the headstock by urging rearwardly the locking lever 59 which was engaged precedingly for locking the member 58 with reference to the body 38 as provided by the bolt 60 carried by said lever and submitted to the return spring 61 shown in Fig. 9, and if, after giving the desired angular setting to the straight rule 45 in its horizontal plane, the longitudinal carriage B is shifted longitudinally with a view to performing a helical sharpening cut, the rod 49 will assume, by reason of the obliquity given to the rule 45, a transverse movement; this tranverse movement of the rod 49 produces through the steel strips 52 and 55 a rotation of the pulley 51 and consequently of the spindle 39 as provided through the agency of the toothed ring 62, of the spring-urged catch 63 and of the radially subdivided plate 64 rigid with said spindle 39 and provided with a notch 65 adapted to be engaged by the catch 63.

The member 58 is made rigid with the toothed ring 62 through the agency of a worm 66 carried by said toothed ring 62 and meshing with an annular series of teeth 67 on the member 58.

To obtain a uniform angle of cut, whatever may be the stage of operation, during the sharpening of tools provided with a plurality of series of teeth such as a milling cutter, the cutter carried by the headstock K is mounted in a manner such that the first tooth to be sharpened is located in contacting relationship with the grinding wheelv This operation is performed while the member 59 is held fast by the bolt 69. At this moment the rotation of the worm 66 connected with the headstock through the agency of the parts 62, 63, 65 and 64 drives the cutter to be sharpened in a manner such that the grinding wheel may execute a cut the depth of which depends on the rotation assumed by said worm 66.

When it is desired to sharpen the next tooth, it is sufiicient to raise the catch 63 and to produce a rotation of the cutter through the subdivided plate 64.

In the case of the sharpening of a cutter or of a tool having a helical line of cut, the above arrangement is associated with that precedingly described and including the angularly adjustable straight rule 45, the rod 49, the pulley 511 and the parts associated therewith.

What I claim is:

A machine for grinding and truing work; comprising; a stationary frame; a work carriage mounted on said frame for horizontal movement in opposite directions; a tool carriage mounted on said frame for movement in opposite directions transverse to the movement of said work carriage; an upright mounted on said tool carriage for pivoting thereon about a vertical axis; a vertical slideway on said upright; a slider on said vertical slideway; a unit including a motor and grinding wheel spindle drivingly connected thereto, said unit including a bearing member; means mounting said bearing member on said slider for pivoting about a horizontal axis; said slider having a portion thereof disposed substantially in the vertical plane of the center of balance of said unit; vertically adjustable mechanical support means engaged between said tool carriage and the lastnamed portion of said slider for supporting said unit on said upright; hydraulic piston and cylinder means operating in conjunction with said mechanical support means for controlling the vertical movements of the slider, whereby to compensate play due to the reaction of the grinding wheel to contact with the work; means engaged between said frame and the tool carriage for controlling the transverse movements of the latter, comprising a worm rotatably mounted on said frame, means for rotating the worm, a nut threadedly engaging said worm so as to be shifted by rotation of said worm, and hydraulic cylinder and piston means engaged between said nut and tool carriage for selectively urging said nut in one direction or the other transverse to the movement of the work carriage.

References Cited in the file of this patent UNITED STATES PATENTS 657,905 Lea Sept 11, 1900 1,870,764 Aeppli Aug. 9, 1932 2,258,510 Laessker Oct. 7, 1941 2,345,986 Mentley et al. Apr. 4, 1944 2,418,738 Talboys Apr. 8, 1947 2,486,108 Brunel Oct. 25, 1949 2,597,648 Lucas May 20, 1952 FOREIGN PATENTS 804,632 France Aug. 10, 1936 

